<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 伪元素两个冒号 */
        div::first-letter {
            font-size: 30px;
            color: #00f;
        }
        /*  */
        div::first-line{
            background-color: yellow;
        }

        div::before{
            content: "aaaaaaaaa";
        }

        div::after{
            content: "cccccccc";
        }
        
    </style>


</head>

<body>

    <div>Lorem ipsum dolor sit amet consectetur adipisicing elit. Cupiditate laboriosam aperiam dolores molestias dolore
        iusto cum unde eos itaque assumenda explicabo, illum accusamus in quis, quidem maiores, qui obcaecati nesciunt.
    </div>

</body>

</html>